[OPTICAL REVIEW Vol. 8, No. 1 (2001) 1-8]
Radiometry and Radiation Efficiency of Twisted Gaussian Schell-Model Sources
Petter ÖSTLUND and Ari T. FRIBERG
Royal Institute of Technology, Department of Physics-Optics, SE-100 44 Stockholm, Sweden
(Recieved August 29, 2000; Accepted October 27, 2000)
Wavefields endowed with the coherence-induced property of optical twist have recently attracted a good deal of theoretical and experimental attention. We present the generalized radiometric theory of fields generated by twisted Gaussian Schell-model sources. The effects introduced by the novel, rotationally symmetric, twist phenomenon in the radiant intensity, generalized radiance, radiant emittance (irradiance), and the radiation efficiency are assessed. The radiance becomes directionally skewed as a result of the twist, whereas the radiant intensity remains axially symmetric. The twist reduces the radiation efficiency and broadens the radiation distribution, in agreement with the notion that the twist decreases the effective coherence. Several special cases, such as quasihomogeneous sources, are analyzed in detail. The radiometric results, which are physically consistent with the superposition models of twisted sources, are demonstrated by illustrative examples.
Key words : generalized radiometry, optical twist, Gaussian Schell-model sources, partial coherence, radiant intensity, radiation efficiency, radiance, radiation transfer